Viscosity of Biological Fluids. 22.3.12. Viscosity is a property of flowing fluid which opposes relative motion of its layers in contact. Because of viscosity a force must be applied to move one layer of liquid past another Types of fluids: Newtonian Non Newtonian Viscoelastic
Viscosity is a property of flowing fluid which opposes relative motion of its layers in contact. Because of viscosity a force must be applied to move one layer of liquid past another
In Laminar flow, the central axis of flow moves with the highest velocityand the successive cylindrical laminae moves progressively more slow as one moves from central axis to the wall
Laminar flow has a parabolic front
A flow in which the elements of the fluid move irregularly in axial, radial and circumferential directions. It occurs at different velocities which fluctuates randomly. The velocity difference across the container changes erratically
Negative sign shows that F acts in a direction opposite to the one in which the layers move
For all Newtonian fluids in laminar flow the shear stress is proportional to the strain rate in the fluid where the viscosity is the constant of proportionality.
The viscoelasticity of blood is traceable to the elastic red blood cells, which occupy about half the volume.
Typical mammalian erythrocytes: (a) seen from surface; (b) in profile, forming rouleaux